How to write an AVI file with in-suit changing time

[skyfighter]

Hi all,

I have a PCO sensicam CCD, and I can program it to read frames. However, the frame reading time is unstable when I run the CCD. Since the CCD is for academic application, the AVI file should be replayed at exact time that each frame obtained rather than at fix fps (frame per second). However, if we use the IMAQAVIcreate vi, the fps is fixed.

Thanks!

[JvdZ]

No replies yet... I having the same problem here for synchronizing video images of a crack with the load applied. It's difficult to sync peaks in the load data with crack propagation seen in the video. The best thing to have should be a clock running within the video frame.

My solution until now is a snapshot video capture in a timed loop, while the data acquisition of the load is running in that same loop. It is synchronized but the framerate is much lower...

[Francois Normandin]

No replies yet... I having the same problem here for synchronizing video images of a crack with the load applied. It's difficult to sync peaks in the load data with crack propagation seen in the video. The best thing to have should be a clock running within the video frame.

My solution until now is a snapshot video capture in a timed loop, while the data acquisition of the load is running in that same loop. It is synchronized but the framerate is much lower...

The solution I've implemented until now was to add a string containing the time the image was captured, as you said above. However, you could also use tags to save this information with each capture. Then, there would be a need to read the tag and wait for the right amount of time before displaying the image. This way, you could get the appropriate illusion. For fast frame rate, you will still have jitter if you rely on Windows' clock (1ms resolution).

[JvdZ]

The solution I've implemented until now was to add a string containing the time the image was captured, as you said above. However, you could also use tags to save this information with each capture. Then, there would be a need to read the tag and wait for the right amount of time before displaying the image. This way, you could get the appropriate illusion. For fast frame rate, you will still have jitter if you rely on Windows' clock (1ms resolution).

Ok, that's an interesting solotion for the problem. A few questions left; did you manage to add the string with the time in the picture itself? Or is it a parallel running string with a kind of list with all the data of the captured images? If possible, could you post an example of the file or a screenshot of the idea?

I'm still stuck to the windows clock, but the resolution of 1ms is not a problem, my framerate will not exceed the 5fps.